Preparation of EDTA-modified magnetic attapulgite chitosan gel bead adsorbent for the removal of Cu(II), Pb(II), and Ni(II)

Attapulgite (ATP) has a unique porous layered chain structure and is an excellent environment-friendly decolorizer. However, its high viscosity makes it difficult to separate. First, it was combined with magnetic Fe3O4 nanoparticles to obtain Fe3O4-ATP that is easy to recycle and reuse. Then, Fe3O4-ATP nanoparticles were embedded in chitosan (CS) gel beads, and glutaraldehyde was used for cross-linking and curing. Lastly, ethylenediaminetetraacetic acid (EDTA) was successfully connected to Fe3O4-ATP/CS gel beads through amidation reaction, which further increased the capability of the adsorbent to adsorb heavy metal ions. The prepared magnetic composite adsorbent is a sphere with a rough surface and porous structure. The maximum adsorption capacity of the prepared Fe3O4-ATP/EDTA/CS adsorbent for Pb(II), Cu(II), and Ni(II) is 368.32, 267.94, and 220.31 mg g−1, respectively. After 5 times of repeated use, Fe3O4-ATP/EDTA/CS still showed good adsorption capacity for Cu(II), Pb(II), and Ni(II). Fe3O4-ATP/EDTA/CS has a large adsorption capacity for heavy metal ions, a wide pH applicability, good reuse, and rapid magnetic separation. In addition, Cu(II) loaded Fe3O4-ATP/EDTA/CS also showed good catalytic degradation performance for bisphenol A. This study prepared a new type of adsorbent with good adsorption performance and provided a promising method for the treatment of wastewater. •Fe3O4 nanoparticles can make attapulgite easy to recycle and reuse.•The introduction of CS and EDTA structures greatly improves the adsorption capacity of the adsorbent for heavy metal ions.•The adsorbent after adsorbing Cu(II) can still be used for the catalytic degradation of BPA.•Good stability provides further possibilities for the practical application of adsorbents.